The Dose Ledger
Retatrutide trial doses, read closely. An independent editorial project.
Evidence

Retatrutide Results by Dose: Every Published Trial Number

Updated 21 Sept 202610 min read8 sources
A precision laboratory balance with a small glass bottle on the pan
-24.2%
weight, 12 mg, 48 weeks
-2.02
HbA1c points, 12 mg, 24 weeks
-82.4%
liver fat, 12 mg, 24 weeks
-15.3%
weight, 12 mg, 40 weeks, phase 3 diabetes

This is the results table, dose by dose, from every peer-reviewed retatrutide trial: obesity, type 2 diabetes, liver fat, body composition, and the first phase 3 publication in 2026. No anecdotes, no forum reports, only the numbers the journals printed.

The short version

  1. Obesity, 48 weeks (NEJM 2023): mean weight change -8.7% at 1 mg, -17.1% at 4 mg, -22.8% at 8 mg and -24.2% at 12 mg, versus -2.1% with placebo.
  2. Type 2 diabetes, 24 weeks (Lancet 2023): HbA1c fell 0.43 points at 0.5 mg, 1.30 to 1.39 at 4 mg, 1.88 to 1.99 at 8 mg and 2.02 at 12 mg; weight at 36 weeks fell 3.19% to 16.94% across the same doses.
  3. Liver fat, 24 weeks (Nature Medicine 2024): relative reduction of 42.9% at 1 mg, 57.0% at 4 mg, 81.4% at 8 mg and 82.4% at 12 mg; normal liver fat reached by 86% of the 12 mg group.
  4. Phase 3 type 2 diabetes, 40 weeks (Lancet 2026): HbA1c -1.69, -1.86 and -1.94 points and weight -11.5%, -13.9% and -15.3% at 4, 9 and 12 mg.

One table, every dose

Weekly doseWeight, obesity, 48 wkHbA1c, T2D phase 2, 24 wkWeight, T2D phase 2, 36 wkLiver fat, 24 wkWeight, T2D phase 3, 40 wk
Placebo-2.1%-0.01-3.00%+0.3%-2.6%
0.5 mgn/a-0.43-3.19%n/an/a
1 mg-8.7%n/an/a-42.9%n/a
4 mg-17.1%-1.30 to -1.39-7.92% to -10.37%-57.0%-11.5%
8 mg-22.8%-1.88 to -1.99-16.34% to -16.81%-81.4%n/a
9 mgn/an/an/an/a-13.9%
12 mg-24.2%-2.02-16.94%-82.4%-15.3%

Sources by column: Jastreboff 2023 (NEJM), Rosenstock 2023 (Lancet), Rosenstock 2023, Sanyal 2024 (Nature Medicine), Bajaj 2026 (Lancet). Where a dose was studied with two starting doses, the range covers both groups. The doses themselves, how they were reached and what they mean for research vials, are on the retatrutide dosage guide.

What counts as a result on this page

A result here is a number printed in a peer-reviewed paper or in the ClinicalTrials.gov results section, from a randomised trial with a placebo group, reported by dose. That rules out press releases, conference slides without a paper, forum reports and before-and-after photos. It leaves six publications between 2022 and 2026, and they are enough to describe what each retatrutide dose did across four outcomes: body weight, HbA1c, liver fat and body composition.

Obesity: weight change by dose

The NEJM phase 2 trial is the reference result. 338 adults with a BMI of 30 or more (or 27 to 30 with a weight-related condition), no diabetes, randomised to placebo or to 1, 4, 8 or 12 mg once weekly for 48 weeks. The primary endpoint was the 24-week weight change; 48 weeks was a secondary endpoint.

Retatrutide phase 2 obesity trial: mean percent change in body weight by weekly dose at 24 and 48 weeksBar chart. Placebo minus 1.6 percent at 24 weeks and minus 2.1 at 48 weeks. 1 mg minus 7.2 and minus 8.7. 4 mg minus 12.9 and minus 17.1. 8 mg minus 17.3 and minus 22.8. 12 mg minus 17.5 and minus 24.2. Source: Jastreboff et al., NEJM 2023, 338 adults with obesity.Body weight change by weekly dose (least-squares mean, %)0-5%-10%-15%-20%-25%-1.6%-2.1%Placebo-7.2%-8.7%1 mg-12.9%-17.1%4 mg-17.3%-22.8%8 mg-17.5%-24.2%12 mg24 weeks (primary endpoint)48 weeks
Phase 2 obesity trial, 338 adults, once-weekly subcutaneous retatrutide for 48 weeks. The 4 mg and 8 mg values pool the two starting-dose groups. Source: Jastreboff et al., NEJM 2023, DOI 10.1056/NEJMoa2301972.

Three details behind the bars. The 4 mg and 8 mg results pool two starting-dose groups each (2 mg and 4 mg starts), which the abstract reports as combined groups. The thresholds at 48 weeks were 92%, 75% and 60% of the 4 mg group losing at least 5%, 10% and 15%; 100%, 91% and 75% at 8 mg; and 100%, 93% and 83% at 12 mg, against 27%, 9% and 2% with placebo.

And the curves had not flattened: every retatrutide group lost more between week 24 and 48, which shapes the duration question covered in the cycle length guide.

Simple version

At 12 mg, people lost about a quarter of their body weight in 48 weeks. At 8 mg, almost as much.

Type 2 diabetes: HbA1c and weight by dose

The Lancet phase 2 trial enrolled 281 adults with type 2 diabetes (HbA1c 7.0 to 10.5%, BMI 25 to 50) on diet and exercise or metformin, and compared retatrutide with placebo and with dulaglutide 1.5 mg. HbA1c at 24 weeks was the primary endpoint.

Change in HbA1c at 24 weeks by treatment group in the retatrutide phase 2 type 2 diabetes trialPlacebo minus 0.01 percentage points; dulaglutide 1.5 mg minus 1.41; retatrutide 0.5 mg minus 0.43; 4 mg with 2 mg start minus 1.39; 4 mg without escalation minus 1.30; 8 mg slow escalation minus 1.99; 8 mg fast escalation minus 1.88; 12 mg minus 2.02. Source: Rosenstock et al., Lancet 2023.HbA1c change from baseline at 24 weeks (percentage points)Placebo-0.01Dulaglutide 1.5 mg-1.41Reta 0.5 mg-0.43Reta 4 mg (2 mg start)-1.39Reta 4 mg (no escalation)-1.30Reta 8 mg (slow)-1.99Reta 8 mg (fast)-1.88Reta 12 mg-2.02
Least-squares mean change in HbA1c at 24 weeks, 281 adults with type 2 diabetes. Source: Rosenstock et al., Lancet 2023, DOI 10.1016/S0140-6736(23)01053-X.

Every retatrutide dose of 4 mg and above matched or beat dulaglutide on HbA1c, and 8 mg slow escalation and 12 mg beat it with statistical significance. Weight at 36 weeks fell 3.19% at 0.5 mg, 7.92% and 10.37% in the two 4 mg groups, 16.81% and 16.34% in the two 8 mg groups, and 16.94% at 12 mg, against 3.00% with placebo and 2.02% with dulaglutide.

The near-identical 8 mg and 12 mg figures in this population are one of the clearest signs of a plateau in the whole program. The diabetes data is read more closely in the type 2 diabetes dose guide.

A precision balance weighing pan close-up with a tiny glass bottle
A precision balance weighing pan close-up with a tiny glass bottle. Editorial photograph.

Liver fat by dose

The Nature Medicine substudy took 98 participants from the obesity trial who had metabolic dysfunction-associated steatotic liver disease with at least 10% liver fat on imaging, and measured the relative change at 24 weeks.

Relative change in liver fat at 24 weeks by retatrutide dose in the MASLD substudyPlacebo plus 0.3 percent; 1 mg minus 42.9 percent; 4 mg minus 57.0 percent; 8 mg minus 81.4 percent; 12 mg minus 82.4 percent. Source: Sanyal et al., Nature Medicine 2024, 98 participants.Liver fat, relative change from baseline at 24 weeks (%)Placebo+0.3%1 mg-42.9%4 mg-57%8 mg-81.4%12 mg-82.4%
Substudy of the phase 2 obesity trial in 98 participants with metabolic dysfunction-associated steatotic liver disease and at least 10% liver fat. Source: Sanyal et al., Nature Medicine 2024, DOI 10.1038/s41591-024-03018-2.

Normal liver fat (under 5%) was reached at 24 weeks by 27% of the 1 mg group, 52% at 4 mg, 79% at 8 mg, 86% at 12 mg and 0% on placebo. The authors report that the liver fat reductions tracked changes in body weight, abdominal fat and markers of insulin sensitivity. As with weight, 8 mg and 12 mg were almost indistinguishable.

Body composition: fat mass and lean mass

A DXA substudy of the diabetes trial, published in The Lancet Diabetes and Endocrinology in 2025, measured total fat mass at 36 weeks in 189 enrolled participants (103 with both scans). Fat mass fell 4.9% at 0.5 mg, 15.2% at 4 mg (pooled), 26.1% at 8 mg (pooled) and 23.2% at 12 mg, against 2.6% with dulaglutide and 4.5% with placebo.

The authors conclude that the proportion of lean mass lost relative to total weight lost was similar to other obesity treatments, and that a greater share of lean mass was not lost despite the larger total loss. That is the only published dose-by-dose body-composition data for retatrutide.

The first phase 3 results (2026)

TRANSCEND-T2D-1, published in The Lancet in June 2026, is the first retatrutide phase 3 paper. 537 adults with type 2 diabetes inadequately controlled by diet and exercise received 4, 9 or 12 mg once weekly or placebo for 40 weeks. HbA1c fell by 1.69, 1.86 and 1.94 percentage points (placebo 0.81), and weight by 11.5%, 13.9% and 15.3% (placebo 2.6%).

Discontinuation for adverse events was 2 to 5% on retatrutide and 0% on placebo, with no severe hypoglycaemia. The obesity phase 3 trials, TRIUMPH-1 to TRIUMPH-4, are marked completed on the registry with primary endpoints at weeks 68 and 80; this page will carry their numbers when a peer-reviewed paper is out. Their design is described in the TRIUMPH and TRANSCEND guide.

Questions readers ask

What are the retatrutide results at 12 mg?

In adults with obesity, -24.2% body weight at 48 weeks, with 100% losing at least 5%, 93% at least 10% and 83% at least 15%. In type 2 diabetes, HbA1c down 2.02 points at 24 weeks and weight down 16.94% at 36 weeks (phase 2), and HbA1c down 1.94 points with weight down 15.3% at 40 weeks (phase 3).

What are the retatrutide results at 4 mg?

-17.1% body weight at 48 weeks in the obesity trial (92% lost at least 5%), HbA1c down 1.30 to 1.39 points in the phase 2 diabetes trial, and -11.5% weight with HbA1c down 1.69 points in the 40-week phase 3 diabetes trial.

Are there retatrutide results beyond 48 weeks?

Not yet in peer-reviewed form. The TRIUMPH phase 3 trials, with primary endpoints at week 68 and 80, completed in late 2025 and 2026 according to the registry; their publications are pending. This page will add them when they appear with a DOI.

Do the results include people's personal experiences?

No. This page reports trial results only: randomised, placebo-controlled, peer-reviewed. Individual reports are not results in the scientific sense and are not used here.

Sources

Reviewed against the primary sources on 21 Sep 2026. Every DOI resolves on CrossRef and every NCT number on ClinicalTrials.gov.

  1. Jastreboff AM, Kaplan LM, Frias JP, et al. Triple-Hormone-Receptor Agonist Retatrutide for Obesity: A Phase 2 Trial. New England Journal of Medicine. 2023;389(6):514-526. doi.org/10.1056/NEJMoa2301972
  2. Rosenstock J, Frias J, Jastreboff AM, et al. Retatrutide, a GIP, GLP-1 and glucagon receptor agonist, for people with type 2 diabetes: a randomised, double-blind, placebo and active-controlled, parallel-group, phase 2 trial conducted in the USA. The Lancet. 2023;402(10401):529-544. doi.org/10.1016/S0140-6736(23)01053-X
  3. Sanyal AJ, Kaplan LM, Frias JP, et al. Triple hormone receptor agonist retatrutide for metabolic dysfunction-associated steatotic liver disease: a randomized phase 2a trial. Nature Medicine. 2024;30:2037-2048. doi.org/10.1038/s41591-024-03018-2
  4. Coskun T, Wu Q, Schloot NC, et al. Effects of retatrutide on body composition in people with type 2 diabetes: a substudy of a phase 2, double-blind, parallel-group, placebo-controlled, randomised trial. The Lancet Diabetes and Endocrinology. 2025. doi.org/10.1016/S2213-8587(25)00092-0
  5. Bajaj HS, Welch M, Shah P, et al. Efficacy and safety of retatrutide, a GIP, GLP-1, and glucagon receptor agonist, in people with type 2 diabetes and inadequate glycaemic control with diet and exercise (TRANSCEND-T2D-1): a double-blind, randomised, phase 3 trial. The Lancet. 2026;407(10546):2402-2413. doi.org/10.1016/S0140-6736(26)00967-0
  6. Urva S, Coskun T, Loh MT, et al. LY3437943, a novel triple GIP, GLP-1, and glucagon receptor agonist in people with type 2 diabetes: a phase 1b, multicentre, double-blind, placebo-controlled, randomised, multiple-ascending dose trial. The Lancet. 2022;400(10366):1869-1881. doi.org/10.1016/S0140-6736(22)02033-5
  7. ClinicalTrials.gov. TRIUMPH-1: retatrutide once weekly in participants without type 2 diabetes who have obesity or overweight. Phase 3; 2,335 participants; primary endpoint at week 80. clinicaltrials.gov/study/NCT05929066
  8. ClinicalTrials.gov. TRIUMPH-4: retatrutide once weekly in participants with obesity or overweight and knee osteoarthritis. Phase 3; 445 participants; primary endpoints at week 68. clinicaltrials.gov/study/NCT05931367

Back to the retatrutide dosage guide